I'm Kurt Terrani. I'm a Senior Staff Scientist at Oak Ridge National Laboratory, and I'm the Technical Director of
the Transformational Challenge Reactor or TCR.
TCR is a small reactor – we call it a micro reactor. It's an advanced reactor, it's cooled with a helium gas,
so you can go to much higher temperature than currently operating nuclear reactors. What's important about it
is that we haven't built an advanced reactor in this country [the United States] in about four decades – 40 years.
But really, it's the wrong philosophy. So basically, you know, the old philosophy's that,
"Let's take one of these dragons from the 'Game of Thrones' series, and put the dragon – it's a very powerful being,
OK – put the dragon inside of the cage, OK, and harness its power. But you know what? If the dragon gets out,
it's gonna be a mess, right? So let's put a few other cages around it and let's call that ‘defense in depth’, OK?
So this is how we convince ourselves that we're safe. But occasionally some extreme event happen and the dragon
gets out and we're all concerned, OK? Well we're saying today is that instead of putting one of those dragons in there,
get a hamster, get a little bunny. So lower your power density.
Under the TCR program, we're 3D printing a core that's 0.8 meter diameter, 0.8 meter tall. You know, maybe a large
keg of beer. It consists of micro-encapsulated nuclear fuel particles – they are nuclear fuel with some coating layers
around them that keep all the radionuclides inside. These particles are inside a 3D printed silicon carbide matrix
that forms a complex fuel block. This is a Cadillac of nuclear fuel. It's got all these barriers to radionuclide release.
It's in a refractory ceramic carbide matrix. It can go to very, very high temperatures, withstand very, very harsh
environments. So we take our fuel, these fuel blocks, and then we combine them with what we call a 'moderator', which
you need to slow down the neutrons that have a small core. And we want to have hydrogen in it. So for moderator,
we're using yttrium hydride, that's one of these, again, brand new materials that hasn't been used before.
And we basically combine the yttrium hydride and stainless steel structures and put our silicon carbide fuel blocks
around it. And that forms our core – and all these components are additive and advanced manufactured.
And mass manufacturing brings that into the third thing we do: when when we are 3D printing, we sneak in some sensors,
we sneak in, we embed sensors in there.
So we generate hundreds of gigabytes of data compressed when we make a part. And we feed that data into our
machine learning algorithms that we're training today to try to correlate these signatures that we see during advanced
manufacturing to final performance of the part.
The machine learning algorithm doesn't need health insurance, pension, you know, so, automate this and step away.
And they can be far more powerful than a human judgment, OK? Because they can process a lot more data.
So for the first time, we have an incredibly data rich approach to qualification.
The two are very distinct. The accident that happened in Ukraine, in Chernobyl is – it happened to a reactor that had
an inherent design flaw, OK? The Western reactors, since the beginning, they've always been built that there's this thing
called the ‘negative feedback’, OK? So if things get hot, if the temperatures go up, by – not because some pump activates
or things like that – by laws of physics, the fission reaction stops, OK? The Eastern reactor, or the RBMK in Ukraine
that happened in Chernobyl, it didn't have that negative feedback. That was a wholly different class of a disaster.
OK. But now let's take a look at the Western reactors that, again, TMI and Fukushima represent. This goes back to
the same conversation we're having, you know, that the design and the philosophy of building these systems was 1950s
and '60s philosophy, OK? So what they did, in a nutshell, they came in and they said, "Hey, let's define these, these really
extreme scenarios," OK? let's call these bounding design basis accidents, and they define these extreme scenarios.
And they said, "Anything that happens beyond that is beyond design basis, it's really not going to happen."
But in Fukushima, you know, they didn't design for a 9.9-plus Richter magnitude earthquake. A tsunami comes in and this
disaster happened.
You got to dial that down. You got to bring that power density down. And then you have inherently benign systems,
systems that are not susceptible. You don't need these active safety systems. When you remove that, then you remove all
this concrete, all this shield, all this containment, all this battery. So the cost comes down. So we need simpler,
smaller, more benign systems. People have known this for a very long time. But the problem is that when you haven't
built anything since late 1970s, OK, when we were when you were still stuck with 1950s and 60s technology,
you can't implement these changes. So that's what we're trying to do is to demonstrate new advanced systems
that have inherently safe, without – you know, you don't want to have a big exclusion zone around them or things like that.
You can drop them in different places, connect them to the grid, and they can be load-following. The whole
infrastructure is moving in that direction. And you know, and, and the new nuclear with a smaller, lower power, micro
reactors really lends itself to this new landscape.
Ultimately, the vision is to go ahead and build affordable, reliable, inherently safe and proliferation-resistant
systems, OK, that you can ship around the world. You know, and I think the best analogy to think about, when you
think of these small nuclear reactors – think of them as a battery, OK? It's a battery that fits in the back of the truck.
And it can go around and you draw from it when you need it. But the battery lasts how long? It doesn't last the day,
it doesn't last two days, it doesn't last – it lasts 20 years, it lasts 15 years. It's compacted, you pick it up, you take it back,
there's no there's no on-site, you know, refueling or anything like that. It's a one-time core, it operates and then you,
you recycle it. So this is the vision that exists today. It's a very sensible vision. And again, it really, it lends
itself to having a balanced portfolio along with renewables and other sources to bring down the carbon consumption.